Combinational scissor-grasper tool for use in laparoscopy

ABSTRACT

Disclosed is a four-jawed combinational scissor-grasper surgical tool for use in laparoscopy. Cutting and grasping functionalities are respectively enabled via movement of a pair of such specially contoured jaw members sliding against or splaying apart from the other pair. Also disclosed are means for achieving selectable interlocking of jaw members and mechanical linkage for their actuation by human user.

FIELD OF THE INVENTION

The present invention generally relates to art of surgical tools andmore specifically to the architecture and operation of a bi-functionalscissor-grasper tool capable of being used in minimally invasivesurgical procedures such as laparoscopy.

BACKGROUND OF THE INVENTION

Past few decades have seen vast development as to surgicalprocedures—minimally invasive surgery being one of the prime advances ofthis era. Minimally invasive surgeries, such as arthroscopic surgery andlaparoscopic surgery, recently have become widely practiced surgicalprocedures. Such procedures have gained rapid popularity and generallyare preferable over the traditional open surgery which requires cuttinglarge incisions through the skin, muscles and membranes to open andexpose the body cavity, thereby necessitating longer hospitalizationstays and prolonged recovery periods. In minimally invasive surgery,small incisions are made into which tubular conduits, such as cannulaeand trocars, are inserted and directed to the site of the operableinternal organ or tissue. One or more surgical instruments areintroduced, each through individual tubular conduits in order to performthe surgical procedure. It would be obvious to the reader that saidminimally invasive surgical procedures including arthroscopy, endoscopyand laparoscopy owe their realization to special tools capable of accessto intended site of surgery via small incision made to body of patientand operation of which allows precise performance of intendedsite-specific surgical manipulations.

Cutting, grasping, suturing, cauterization, distension, stapling formcommonality of operations in surgery. Minimally invasive surgery toolsof art do provide individually for such functions. However, due to thesingularity of function accorded by such tools available, theinterchange of tools amidst operations and efforts, time required forsuch becomes unavoidable, besides causing opportunity for complicationsduring repeated insertion and removal of different tools.

In laparoscopic surgery, specialized long thin tools are inserted viaair-tight ports fixed on the CO₂ inflated abdomen of the patient. Theoperation area as seen by the endoscope is displayed on an externaldisplay where the surgeon views it.

Since only a few thin holes are created for inserting tools, this typeof surgery results in fewer injuries to the patient, faster healingperiods and less cosmetic damage. This type of surgery requiresspecialized tools that are characterized by their long shafts (usuallyaround 300 mm) and thin cross sections (usually 5-8 mm dia). These toolscome in various end-tips, such as scissors, blades, graspers, etc.Procurement/maintenance costs, sterilization requirements of additionalequipment are other problems faced by the medical fraternity. Thus,development of minimum invasive surgical tools capable of pluralfunctionality, yet maintaining accuracy, precision and ease of use, arepressing needs of art.

There have been some attempts for resolving said needs of art. Variousforms of laparoscopy tools, housings for positioning instruments,extendible blades, multifunctional scissor jaw designs and the like findmention in the art. Many devices which are used commonly for grasping orcutting objects have two elements which can be moved towards one anotherand away from one another. The elements have surfaces which may be bluntor sharp so that an object positioned between them may be either graspedor cut when the elements are moved towards one another. Examples of suchdevices include tongs, tweezers, forceps, scissors, guillotines, andwire cutters. Such devices can also be adapted to dissect tissue, forexample, by placing the elements of the device into or next to an objectand then causing the elements to splay apart thereby dissecting theobject. However, these designs have been found to suffer from drawbackscritically affecting their intended function.

U.S. Pat. No. 6,024,744 discloses a combined bipolar scissor andgrasper. The instrument disclosed in this patent is a combined bipolarelectrosurgical cutting and grasping instrument where the graspingsurfaces are contained within the shape of a standard surgical scissor.Accuracy of operation is defined by precise positioning of theseportions at site of manipulation. However, being contained within samearm, the cutting and grasping portions are invariably in same angle ofmotion, thus present risk of accidental cuts or clamps. Also, pivotingof the tool while being inserted is not without risk due to exposedcutting edges.

U.S. Pat. No. 5,397,325 discloses a surgical suturing device which has atubular elongated shaft terminating into a jaw assembly at the distalend and a handle assembly at the proximal end thereof. The jaw assemblyincludes a first jaw member pivotally connected to a second jaw member.An actuator rod extending longitudinally within the length of said shaftis connected at its proximal end to said handle assembly and ispivotally connected at its distal end to said jaw assembly. Theunderside of said first jaw member is provided with a cupped recesshaving a wheel assembly disposed therein. The wheel assembly includes aneedle mount for securely retaining a needle and is configured such thatthe needle lies within the cupped recess when the jaw members are closedand can be deployed in a protracted position away from the first jawmember when the jaw members are in an open position. In operation, thesuturing device offers superior control over both the needle and thetissue to be sutured.

The above mentioned invention suffers from drawback of limited degree ofoperation due to configuration wherein only one jaw is movable and theother fixed. The said single shaft device presented finds utility forfunction of suturing having adequate needle control, however, does notoffer means to grasp and stabilize the tissue, which is slippery bynature thus mandating that the tissue tending to evade needle carriermanipulation must be grasped by a second instrument. As a result, thesurgeon encounters difficulty in controlling and positioning both theneedle and the tissue simultaneously, and the patient can suffercomplications such as frayed tissue, errant punctures, inadequatestitches, extended surgical duration, hemorrhaging, and the like.

U.S. Pat. No. 5,509,923 describes a device for dissecting, graspingand/or cutting an object has at least two elongate elements at least aportion of at least one of the elements is formed from a pseudoelasticmaterial, preferably a pseudoelastic shape memory alloy. End portions ofthe elements can be moved away from one another and then toward oneanother to dissect, grasp and/or cut an object with the elements. Incertain embodiments, the device further comprises an actuating means andat least a portion of the elements and/or the actuating means is formedfrom a pseudoelastic material. The device is intended for applicationsincluding dissecting, grasping and/or cutting objects located indifficult to reach areas, within the body during surgery. However, thecutting/grasping members of this tool are pseudoelastic and thus, allowlimited degree of choice while deciding on the angle of cut and portionof tissue being grasped. Unintentional nicks and pinches cannot be ruledout are limitations in rotational ability of the tool proposed.

Laparoscopic Scissor Grasper, a product by Interventional and Surgicalinnovations LLC is a minimally invasive surgery tool that can both cutand grasp with aid of two jaws having mated via serrations along theirinner surfaces. The jaws separate along two axes apart and sideways toprovide grasping and cutting functions respectively. However, thisdesign is subject to certain shortcomings as the grasping serrations areinvariably exposed while shearing. Also, pivoting of the jaws abouttheir longitudinal axis is not possible. Also, for cutting edge to work,the chamfered edges necessarily need to press against each other. Thispressure is enabled by forging a slight curvature in cutting arms beingpressed at pivot by means of rivet or other tightening means. Overperiod of use, this arrangement looses its original construction leadingto either loss of pressure of cutting arms or distancing of said cuttingarms which ultimately leads to firstly loss of cutting functionality andsecondly, presence of two sharpened (chamfered) edges which act asknives and can cut whether intended or not. Such occurrence, is thuscompromise to application intended.

U.S. Pat. No. 5,133,727 discloses radial jaw biopsy forceps whichfeature a multi element head having a fixed blade juxtaposed between twograsper jaws having mated serrations along their internal edges forgrip. However, this design too has shortcomings of limited scope formovement and accidental cuts to material in space between the graspingarms while performing delicate functions.

By and large, innovations cited have not been able to overcome theproblems of the art. Design of a pluri-functional device for achievementof surgical operations is a pressing need of the art. The presentinventor has undertaken specific research and has arrived at novelconstruction and operability of a device for addressing said problems ofart. The following brief description presents one non-limitingembodiment of constructing and performing the present invention.

OBJECTS OF THE PRESENT INVENTION

It is an object of the present invention to provide a single shaftfour-jawed laparoscopic instrument with suitable components and linkagesthat provide for cutting-grasping bi-functionality and constructioncapable of performing intended bi-functionality in a manner that allowsinfinite rotational ability about its longitudinal axis.

It is another object of the present invention to provide a single shaftlaparoscopic instrument wherein cutting functionality is enabled viashear forces achieved at edges of jaws by their motion against eachother thus avoiding open blade design altogether.

It is another object of the present invention to provide a four-jawedsingle shaft laparoscopic instrument wherein construction of jawscomprise integral mechanical interlocking system that allows forselectable locking of two pairs of jaws each configuration serving thecutting or grasping functionalities.

It is another object of the present invention to provide a bi-functionalsingle shaft laparoscopic instrument which reduces the amount ofinstrumentation necessary for surgical procedures in which both cuttingand grasping is required.

It is another object of the present invention to provide a bi-functionalsingle shaft laparoscopic instrument which reduces the amount ofdexterity needed by a surgeon performing a surgical procedure in whichboth electrosurgical cutting and grasping is required.

It is another object of the present invention to provide a bi-functionalsingle shaft laparoscopic instrument which is easily amenable to commonart pre-surgical sterilization techniques.

It is another object of the present invention to provide a bi-functionalsingle shaft laparoscopic instrument which is capable of repeated usethus decreasing the amount of medical waste generated in surgicalprocedures.

It is yet another object of the present invention to provide for aminimally invasive surgical tool which efficiently combines functions ofcutting, grasping and overcomes overall drawbacks of prior art devices.

It is also an object of the present invention to achieve accurate finecuts or shear-free firm grasp whenever intended.

It is also an object of the present invention to provide grasping andcutting surfaces which are independent of each other.

These and further objects shall present themselves to the reader upondescription presented herein below along with accompanying drawings.

SUMMARY OF THE PRESENT INVENTION

In accordance with principles of the present invention, a single shaftlaparoscopic instrument is proposed which has cutting/graspingbi-functionality. Said bi-functionality is enabled by achieving twouser-selectable configurations of four specially constructed jawmembers. Design of these jaw members comprises an integral mechanicalinterlocking system and linkage which, when operated by the user,results in two movable elements each comprising a pair of jaws. In oneconfiguration where linkage allows for sliding of the movable elementsagainst each other, cutting function is achieved. In other configurationwhere linkage allows for movement of the movable elements away from andtowards each other, the grasping functionality is achieved.

The invention may be more fully understood by reference to the citedfigures and details of exemplary embodiments. Alternative embodiments ofthe invention as claimed, and providing the benefits of the novelconcepts of the invention, are contemplated and will be obvious from theexplanations hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the preferred embodiment of the presentinvention showing the jaws in the closed position locked in the scissorconfiguration.

FIG. 2 is a perspective view of the preferred embodiment of the presentinvention showing the jaws in the closed position locked in the scissorconfiguration, but with two of the jaws not visible, so as to show theinner locking mechanism of the instrument.

FIG. 3 is a perspective view of the laparoscopic instrument proposed bythe present invention with a magnified view of the four-jawed tip shownin inset.

FIG. 4 (a,b,c) are schematic representation of inter-play between twojaw pairs when in grasping configuration.

FIG. 5 (a,b,c) are schematic representation of inter-play between twojaw pairs when in cutting configuration.

FIG. 6 (a,b,c) are side, front perspective and back perspective views ofjaw element 002/004 of the laparoscopic instrument proposed by thepresent invention.

FIG. 7 (a,b,c) are side, front perspective and back perspective views ofidentical jaw element 001/003 of the laparoscopic instrument proposed bythe present invention.

FIG. 8 illustrates the hinge, described as element 005 in FIGS. 4 and 5

FIG. 9 illustrates the connecting link that enables force to gettransmitted to jaw elements 001 and 003.

FIG. 10 illustrates the inner shaft that connects to the connecting linkshown in FIG. 9 .

FIG. 11 illustrates the hinge member that resides within the distal endof the inner shaft.

FIG. 12 illustrates the pin that allows the connecting link to hingewith jaws 001 and 003.

FIG. 13 illustrates the shifter shaft that engages the jaw elements 002and 004 in order to push them forward or pull them backward in order torespectively convert the tool from the grasper mode to scissor mode orthe other way round.

FIG. 14 illustrates the outer holder of the tool that holds all the jawstogether on the hinge 005, and attaches to the outer shaft 009.

FIG. 15 illustrates the side view of the proposed instrument in thegrasper configuration, with the jaws in open position. Outer holder ishidden in this view.

FIG. 16 illustrates the side view of the proposed instrument in thegrasper configuration, with the jaws in closed position. Outer holder ishidden in this view.

FIG. 17 illustrates the side view of the proposed instrument in thescissor configuration, with the jaws in closed position. Outer holder ishidden in this view.

FIG. 18 illustrates the side view of the proposed instrument in thescissor configuration, with the jaws in open position. Outer holder ishidden in this view.

FIG. 19 illustrates a close-up perspective view of the inner mechanismof the instrument in the scissor configuration with the jaws in closedposition. Outer holder is hidden in this view.

FIG. 20 illustrates a close-up perspective view of the inner mechanismof the instrument in the grasper configuration with the jaws in closedposition. Outer holder is hidden in this view.

FIG. 21 illustrates a perspective view of the inner mechanism of theinstrument in the grasper configuration, with the jaws in closedposition and the connecting links visible. Outer holder and shiftershaft are hidden in this illustration.

The invention may be more fully understood by reference to the citedfigures and details of exemplary embodiments. Alternative embodiments ofthe invention as claimed, and providing the benefits of the novelconcepts of the invention, are contemplated and will be obvious from theexplanations hereinafter.

DETAILED DESCRIPTION OF THE INVENTION

The laparoscopic procedure generally involves creating small incisionsthrough the navel and through the abdominal wall for viewing andoperating on internal areas of the body, such as the uterus, ovaries,gall bladder and appendix. Typically, a trocar tube is introducedthrough the navel incision for receiving a camera, magnifying lens orother fiber optic device for viewing the surgery. One or more additionaltrocar tubes are introduced through incisions in the abdominal wall suchthat laparoscopic surgical tools can be inserted through the tube(s) formanipulating, cutting and/or suturing an internal organ or tissue. Inthis manner, while viewing a video monitor via the fiber optic devicepositioned in the navel trocar, the surgeon can grasp an organ or tissuewith one surgical tool and simultaneously cut or suture with anothersurgical device.

The evolution of minimally invasive surgery has given rise to the needof single-shaft surgical instruments which can be inserted through atrocar and easily manipulated by a surgeon. These instruments arefashioned such that they can be inserted lengthwise through the trocarand comprise hand-held controls on the proximal end thereof to operatethe distal, tissue-manipulating end of said instrument. Single shaftdevices must have a sufficiently small diameter so that they can beinserted into a trocar tube and guided to the operative tissue site.Typically, such instruments are designed to perform one function, suchas grasping and stabilizing tissue, cutting tissue, holding a suturingneedle or pulling a suturing needle through tissue, suctioning andirrigating the fluids, cauterizing the tissue, coagulating blood vesselsand so on. A major drawback to minimally invasive surgery is that itrequires exceptional motor coordination to grasp and stabilize an organor tissue with one surgical tool and performing a cutting or suturingprocedure on said organ or tissue with a second surgical device, allwhile viewing a two dimensional video monitor. This disadvantage isparticularly acute in performing a laparoscopic suturing procedure.

FIG. 1 is a schematic side perspective view of the four jawed tip of thelaparoscopic instrument proposed by the present invention. Also, FIG. 2illustrates elements structurally integral to the jaws of thelaparoscopic instrument proposed by the present invention which providefor interlocking action. Explanation as to construction of thelaparoscopic tool subject of the present invention is now attemptedreferring to both these figures. The combinational scissor-grasper tool000 comprises a bullet nosed end comprising four independent jawelements 001, 002, 003 and 004. Said jaw elements are in operationalassociation with a single hinge 005 and can lock into one another bypositive locking mechanism enabled by mated protrusions and depressionscorresponding to protrusion 006 and depression 007 along respectiveinner surface of each adjacent arm-in-pair. This mechanism ensures thatwhen motion is delivered at the hinge, at all times, a specificcombination of arms moves together.

FIG. 3 illustrates magnified view of the four-jawed tip of thelaparoscopic instrument proposed by the present invention. Asillustrated therein, the four jawed tip 000 is key novel feature of thepresent invention capable of performance between both cutting andgrasping functionalities via actuation of controller 008.

FIGS. 4 (a,b,c) and 5 (a,b,c) are schematic representation of inter-playbetween two jaw pairs when in grasping and cutting configurationsrespectively. When viewed from its tip with the tool being oriented suchthat its hinge 005 hosting the jaw elements 001, 002, 003 and 004 isparallel to the floor (horizontal), locking of jaw 001 with 004 and jaw002 with 003 respectively to each other results in grasper configurationof the tool. In same orientation, locking of the left side jaws 003 and004 and right side jaws 001 and 002 respectively to each other resultsin the scissor configuration of the tool 000.

FIG. 6 (a,b,c) are front, perspective and back views of jaw element002/004 of the laparoscopic instrument 000. It may be seen that 010 is adepression into which the extension 021 illustrated later in FIG. 7 .aenters while the instrument is in the scissor configuration. Generallyreferring to FIGS. 6 to 17 , it may be seen that the shape associatedwith the depression 010 is intended to mate with shape associated withextension 021 so that the two elements can snugly slide into oneanother. 011 is an arc section having its geometric centre at point 012which is geometrically mimicked on the inner arc of extension 021 thusallowing the extension 021 to slide over arc section 011 smoothly. Thismotion is later described in FIG. 15 . Points 012 and 013 determine theend-points of slot 027. The hinge 005 fits into the slot 027. Along theslot 027 jaws 004 and 002 can slide backward and forward such thateither points 012 or 013 align with central axis of hinge 005, to enablethe instrument to function as a grasper or as a scissor, respectively.Jaws 004 or 002 can rotate about hinge 005 either about point 012 orpoint 013. Arcs 014 and 015 define a slot 020. The arc 014 has itsgeometric centre at point 013, while the arc 015 has its geometriccenter at point 012. Protrusion 038 is positioned within the slot 020.Arcs 015 and 016 define the handle 028. The arc 016 has its geometriccentre at point 013. This handle gets positioned into the depression039. When the instrument shifts from grasper to scissor position, theshifter shaft 043 moves forward, towards the distal direction. Duringthis forward motion, the proximal vertical surface 046 of the depression039 pushes against the surface 016. At the same time, the distal surface048 pushes against surface 014. This pushes the jaws 004 and 002forward, towards the distal direction such that they slide on hinge 005along their respective slots 027 taking them from being hinged aboutpoint 012 to being hinged about point 013. As a result of this motion,the protrusion 021 in jaws 001 and 003 gets inserted into depression 010in jaws 002 and 004 respectively, thus locking jaw 001 to 002 and jaw003 to 004. During the same motion, the protrusion 006 in jaws 001 and003 slides out of the depression 007 in jaws 004 and 002 respectively,thus removing the lock between jaws 002 and 003 and between jaws 001 and004. This is the scissor configuration. When the instrument shifts backfrom scissor to the grasper configuration, the shifter shaft 043 movesbackwards, towards the proximal end. During this motion, the distalvertical surface 047 of depression 039 engages with the surface 015.This pulls the jaws 004 and 002 backwards, towards the proximaldirection such that they slide on hinge 005 along their respective slots027 taking them from being hinged about point 013 to being hinged aboutpoint 012. As a result of this motion, the protrusion 021 in jaws 001and 003 gets removed from depression 010 in jaws 002 and 004respectively, thus unlocking jaw 001 from 002 and jaw 003 from 004.During the same motion, the protrusion 006 in jaws 001 and 003 slidesinto the depression 007 in jaws 004 and 002 respectively, thus engagingthe lock between jaws 002 and 003 and between jaws 001 and 004. This isthe grasper configuration. Thus, the protrusion 021 and depression 010form a male-female pair to lock the device in the scissor configuration.The protrusion 006 and depression 007 form another male-female pair tolock the device in the grasper configuration. This switching mechanismbetween grasper and scissor configurations is shown between FIG. 16 toFIG. 17 as a side view and also between FIG. 20 and FIG. 19 as aclose-up perspective view.

When the instrument is in the scissor configuration, the jaws 004 and002 rotate about the point 013 on hinge 005. In this configuration, theshifter shaft 043 has kept the jaws 004 and 002 pushed in this position.Hence, the surfaces 046 and 048 slide over surfaces 016 and 014respectively. As the jaws 004 and 002 rotate about point 013, it isessential that the arcs 014 and 016 have their geometric centers atpoint 013. When the instrument is in the grasper configuration, the jaws004 and 002 rotate about the point 012 on hinge 005. In thisconfiguration, the shifter shaft 043 has kept the jaws 004 and 002pulled in this position. Hence, the surface 047 slides over surface 015.As jaws 004 and 002 rotate about point 012, it is essential that the arc015 has its geometric centre at point 012.

While shifting between scissor and grasper configurations, a singlestroke motion engages one lock and disengages the other. The serratedsurfaces 017 of jaws 004 or 002 and serrated surfaces 026 of jaws 001and 003 are used for the grasping action. The distance between eachtooth of the serrated surfaces 017 and 026 is greater than or equal tothe distance between points 012 and 013. While the tool jaws are in theclosed position and the tool needs to be shifted between scissor andgrasper configurations in either direction, this particular distancebetween the teeth on serrated surfaces 017 and 026 ensures that jaw 004can slide over jaw 003 and jaw 002 can slide over jaw 001, withoutletting the teeth physically interfere with each other.

According to another aspect of the present invention, edge 018 of jaws004 or 002 is hardened and angled to create a sharp shearing edge. Asshown in FIG. 5 .b and FIG. 18 , the edge 018 in jaw 004 moves againstthe edge 018 of jaw 002 to create the necessary shearing action requiredfor the instrument to function as a scissor.

The serrated surfaces 017 and 026 are physically distinct andindependent of the shearing edge 018. This makes it possible to pick agreat variety of grasping serration independently of a variety ofscissor edge. Thus, a large number of combinations of different scissorand grasper types are possible to be incorporated in the instrument.

According to another aspect of the present invention, the handle 028 iscreated with a step 019 such that the depression 039 can be accommodatedwith the protrusion 038 positioned in the slot 020.

The protrusion 021 is of a shape comprising an arc with the geometriccentre at point 023. This curvature also matches with the curvature ofdepression 010. The depression 022 is of a shape comprising an arc withthe geometric centre at point which is offset towards the distal end ofthe tool from point 023 by a distance that is equal to the distancebetween points 012 and 013. This is also the distance by which theshifter shaft 043 moves while switching between the scissor and graspermechanisms. Point 023 is the position of a hole in jaws 001 or 003 inwhich the hinge 005 resides. Jaws 001 and 003 always rotate about theaxis through point 023.

The connecting link 034 hinges to the jaws 001 and 003 at the hole 024using pin 037. Pin 037 can be in the form of a rivet that joins holes033 and 024. A step 025 accommodates the thickness of the connectinglink 034. Inner shaft 045 has a means of connecting with link 034 by apin 031 at holes 032 and 035. The pin 031 can be in the form of a rivet.

The entire system of the inner shaft 045 connected to jaws 001 and 003by means of connecting links 034 hinged respectively at 032 and 033 bypins 031 and 037, is shown in FIG. 21 . The jaws 001 and 003 are forcedto open by a simple parallelogram mechanism when the inner shaft 045 ismoved forward in the distal direction. The connecting links 034 and thedistance between points 023 to 024 on jaws 001 and 003 form the segmentsof this parallelogram mechanism. The user's action at element 008creates this required motion in 045. When the proposed surgical tool isin the grasper configuration, the protrusion 006 in jaws 001 and 003locks in with depression 007 in jaws 004 and 002 respectively, thuslocking jaws 001 and 004 together on one hand, and jaws 002 and 003 onthe other. At this time the protrusion 021 in jaws 001 and 003 anddepression 010 in jaws 002 and 004 are no longer engaged. When the jaws001 and 003 are forced to open up by the parallelogram mechanismmovement initiated by the user acting on inner shaft 045, they also, inturn force jaws 004 and 002 to move along with them respectively. Thiscreates the grasper configuration as shown in FIG. 15 and FIGS. 4 .a,4.b, 4.c.

When the tool is in the scissor configuration, the protrusion 021 injaws 001 and 003 locks in with depression 010 in jaws 002 and 004respectively, thus locking jaws 001 and 002 together on one hand, andjaws 004 and 003 on the other. At this time the protrusion 006 in jaws001 and 003 and depression 007 in jaws 004 and 002 respectively are nolonger engaged. When the jaws 001 and 003 are forced to open up by theparallelogram mechanism movement initiated by the user acting on innershaft 045, they also, in turn force jaws 002 and 004 to move along withthem respectively. This creates the scissor configuration as shown inFIG. 18 and FIGS. 5 .a, 5.b, 5.c.

Thus, when the instrument is in the grasper configuration, jaw 004 lockswith jaw 001 while jaw 003 locks with jaw 002. On the other hand, whenthe instrument is in the scissor configuration, the jaw 004 locks withjaw 003 while jaw 001 locks with jaw 002.

A step 036 is created at the distal tip of inner shaft 045 in order toaccommodate the thickness of connecting link 034. The combined widths ofthe section 036 and two instances of link 034 are accommodated by pin031 within the cut out gap 040 of shifter shaft 043. This in turn mustfit within the cut out gap 041 of outer holder 044. In this outer holder044 the hole 042 holds the hinge 005.

A means to provide for the backward and forward movement of the shiftershaft is created. Any standard method to achieve this in a user-friendlymanner would work. Other requirements of a surgical instrument, such asthe ability rotate and fit within a 5 mm diameter, are also fulfilled.

According to another aspect of the present invention, the surfacesinvolved in grasping and cutting are independent of each other. Hencethey may be sharpened, knurled, and formed independently for optimalperformance.

Since both scissor and grasper operate about the same common hinge 005,there is no inherent need for a 90° rotation about the tool's axis for ashift of configuration.

As described hereinabove, the mechanism for interlocking of jaw elementscomprises male and female locking elements. Said interlocking elementsare completely internal to the jaws themselves and thus do not interferewith the surgical environment.

According to another aspect of the present invention, the mechanism toshift between the grasper and scissor configurations is also containedcompletely internal to arm of the tool. It has so been designed to allowthe tool to be manufactured within a 5 mm diameter. It should beappreciated that the instrument can be provided with a different shapeof jaws to perform other actions besides straightforward grasping andcutting. Different types of graspers, scissors can be incorporated tothis mechanism. The actuation of the instrument may be carried out byeither the means of a regular handle operated by hands or it can bemotorized to be applied in a robotic setting. In either case themechanism of the front tip does not change.

If the jaw members and internal mechanism members are coated withappropriate insulation layers, the function of bipolar cauterization mayalso be added into the tool. The bipolar cauterization will occurbetween the jaw elements when the instrument is in the grasperconfiguration.

According to yet another aspect of the present invention, the mechanismto shift between the grasper and scissor configurations operates with astrictly linear motion along the axis of the tool. Inner and outershafts of the main shaft body 009 are separable and thus, allow forrotation along the longitudinal axis. This allows for the tool to berotated infinitely clockwise or anticlockwise about the axis of its mainshaft body 009 and thus enable a 360° field of operation.

According to another aspect of the present invention, it is intended bythe present inventor to make the device of the present inventionamendable to controllers of common art, thus negating design ofcustomized control architecture and/or user interfaces. This also meanseasy migration between tools for surgeons.

Thus, it would be now evident to the reader that the user interface orcontrolling means is same for both cutting as well as grasping functionsand that the selection of function is enabled via actuation of a switchwhich controls interlocking of pairs of jaws of the device proposed bythe present invention in accordance with functionality required. Thisswitch may be selected among common art easy switching mechanisms suchas turning knobs, trigger or toggle levers. Thus, the user has abilityto migrate from one mode of operation to other with single stroke ofswitch and without having to remove/reinsert in body of patient beingoperated. Further, the scissor grasper combination can be made able towithstand infinite rotation of the tool along its longitudinal axisusing a common art thumb-wheel. As common art controllers are utilized,the user maintains same tactile feel and dexterity while adapting to useof the proposed tool.

According to other embodiments of the present invention, the innershafts of the tool are constructed to allow disassembly and reassemblyto the main outer shaft by means chosen among press-fit, threading/screwmechanism or key-slot mechanism. This makes it possible to easilyautoclave or sterilize the tip of the proposed instrument. It alsoallows for just the tip to be replaced without having to replace thehandle or outer shaft.

According to another embodiment of the present invention, a cleaningport may be introduced in the shaft of the proposed laparoscopic toolfor allowing sterilization and multiple use thereafter.

As will be realized, the present invention is capable of various otherembodiments and that its several components and related details arecapable of various alterations, all without departing from the basicconcept of the present invention. Accordingly, descriptions will beregarded as illustrative in nature and not as restrictive in any formwhatsoever. Modifications and variations of the system and apparatusdescribed herein will be obvious to those skilled in the art. Suchmodifications and variations are intended to come within the scope ofthe appended claims.

We claim:
 1. An apparatus comprising: first, second, third, and fourthjaw elements, the first jaw element comprising a first extension and afirst protrusion, the third jaw element comprising a second extensionand a second protrusion, the second jaw element comprising first andsecond depressions, and the fourth jaw element comprising third andfourth depressions; wherein in a first configuration, the second jawelement is coupled to the first jaw element by the first extensionreceived in the first depression, and the fourth jaw element is coupledto the third jaw element by the second extension received in the thirddepression; and wherein in a second configuration, the second jawelement is coupled to the third jaw element by the second protrusionreceived in the second depression, and the fourth jaw element is coupledto the first jaw element by the first protrusion received in the fourthdepression.
 2. The apparatus of claim 1, further comprising: a shiftershaft comprising a proximal end and a distal end; wherein the distal endof the shifter shaft is coupled to the second and fourth jaw elements;wherein a longitudinal axis is defined through the proximal and distalends of the shifter shaft; wherein on the condition the shifter shaft isin a first position along the longitudinal axis, the apparatus is in thefirst configuration; and wherein on the condition the shifter shaft isin a second position along the longitudinal axis, the apparatus is inthe second configuration.
 3. The apparatus of claim 2, wherein: thefirst, second, third, and fourth jaw elements each comprise a serratedsurface; the serrated surfaces of the first and second jaw elements areconfigured to engage each other; and the serrated surfaces of the thirdand fourth jaw elements are configured to engage each other.
 4. Theapparatus of claim 3, wherein: each serrated surface comprises adjacentteeth on a surface separated by a distance equal to or larger than adistance between the first and second positions of the shifter shaft. 5.The apparatus of claim 2, further comprising: a hinge; wherein each ofthe first, second, third, and fourth jaw elements rotate about thehinge.
 6. The apparatus of claim 5, wherein: each of the second andfourth jaw elements comprise a first slot; and the hinge moves along thefirst slots of the second and fourth jaw elements in a directionparallel to the longitudinal axis.
 7. The apparatus of claim 5, wherein:each of the second and fourth jaw elements comprise a second slotdefined by two arcs; and the distal end of the shifter shaft isconfigured to engage the second slots of the second and fourth jawelements to shift the second and fourth jaw elements relative to thehinge on the condition the shifter shaft is moved between the first andsecond positions.
 8. The apparatus of claim 7, further comprising: aninner shaft comprising a distal end; a pair of connecting links eachcoupled to the distal end of the inner shaft; and a common pin; whereina first link of the pair of connecting links is coupled to the first jawelement; wherein a second link of the pair of connecting links iscoupled to the third jaw element; wherein the first jaw element and thethird jaw element each comprise a hole; and wherein the common pin isinserted through the holes in the first and third jaw elements.
 9. Theapparatus of claim 2 embodied in a medical device, wherein: the firstconfiguration is a cutting configuration of the medical device; and thesecond configuration is a grasping configuration of the medical device.10. The apparatus of claim 1 embodied in a medical device, wherein: thefirst configuration is a cutting configuration of the medical device;and the second configuration is a grasping configuration of the medicaldevice.
 11. A method for configuring first, second, third, and fourthjaw elements into first and second configurations, the methodcomprising: configuring the first, second, third, and fourth jawelements into the first configuration by causing the second and fourthjaw elements to respectively couple to the first and third jaw elementsby first and second depressions receiving first and second extensions,respectively; and configuring the first, second, third, and fourth jawelements into the second configuration by causing the second and fourthjaw elements to respectively couple to the third and first jaw elementsby third and fourth depressions receiving first and second protrusions,respectively; the first and second extensions being provided on thefirst and third jaw elements respectively, and the first and secondprotrusions being provided on the first and third jaw elements,respectively; and the first and second depressions being provided on thesecond and fourth jaw elements, respectively, and the third and fourthdepressions being provided on the second and fourth jaw elements,respectively.
 12. The method of claim 11, further comprising: in thefirst configuration, creating a cutting motion with the first, second,third, and fourth jaw elements by translating an inner shaft coupled ata distal end to the first and third jaw elements; and in the secondconfiguration, creating a grasping motion with the first, second, third,and fourth jaw elements by translating the inner shaft.
 13. The methodof claim 11, wherein: the distal end of a shifter shaft is coupled tothe second and fourth jaw elements; the configuring of the first,second, third, and fourth jaw elements into the first configurationcomprises placing the shifter shaft in a first position along alongitudinal axis; and the configuring of the first, second, third, andfourth jaw elements into the second configuration comprises placing theshifter shaft in a second position along the longitudinal axis.
 14. Themethod of claim 11, wherein the method comprises configuring a surgicalinstrument into the first and second configurations.